public class DuNode<T> {
    T data;
    DuNode<T> prior;
    DuNode<T> next;
    public DuNode(DuNode<T> n){
        next=n;
        prior=null;
    }
    public DuNode(T obj,DuNode<T> n,DuNode<T> p){
        data = obj;
        next = n;
        prior = p;
    }
}
